The inpatient economic burden of antibiotic resistance in Switzerland: a regression-based analysis.

Antimicrobial Resistance is recognized as a critical public health challenge, leading to increased morbidity and mortality. Specifically, antibiotic resistance (ABR) imposes significantly higher healthcare and societal costs compared to infections treatable with standard antibiotics. Although numerous studies emphasize the threat of ABR, no comprehensive bottom-up analysis has been conducted in Europe to precisely quantify the incremental economic burden of resistant infections. This paper aims to fill this gap by analyzing Swiss hospital data across 124 facilities in 2023. We conducted a retrospective, multicenter analysis of 102,492 hospital stays involving bacterial infections of all types, caused by both antibiotic-resistant and antibiotic-sensitive strains. Infection cases were identified using Swiss ICD-10-GM codes: the B9 code group for non-resistant bacteria and the U8 code group for resistant bacteria. These codes are recorded when an infection is treated during hospitalization and indicate the type of pathogen involved. Using regression models and adjusting for demographic, socio-economic, and clinical factors, we estimated the impact of ABR on hospitalization costs, length of stay, mortality and intensive care unit (ICU) admissions. In addition to direct healthcare costs, we assigned a monetary value to: days lost due to hospitalization to derive the productivity losses, years of life lost (YLL) due to higher mortality and short-term losses in health-related quality of life during intensive care stays, expressed as Years Lived with Disability calculated with disability weights. Aggregating the values of these four elements we obtained the incremental economic burden of ABR in percentage and in absolute monetary terms, considering the Average Marginal Effects. ABR was associated with a 11.4% increase in hospitalization costs (+$3,720 per patient) and a 10.8% longer hospital stay (+1.24 days), leading to productivity losses of $450 per patient. Resistant infections resulted also in increased (+13.2%) and more premature mortality (+14.2%), overall translating to 0.11 YLL per patient, with an associated monetary value of $10,926. ICU stays for resistant infections were 37.4% longer, resulting in an additional loss of health-related quality of life, monetised at $159 per patient. The average incremental cost associated with in-hospital resistance was $15,255 per patient (14.7% increase), with a national burden estimated at $60 million with the current incidence. The total burden for a patient with a more severe complexity reaches $34,419. These findings underscore the significant health and economic burden of ABR in Switzerland. The estimated impact is particularly pronounced among patients with higher clinical complexity, for whom the per-patient burden more than doubles. Since total burden estimates depend on the incidence of resistant infections, any increase in incidence would translate into a higher aggregate burden, holding per-patient effects constant. By providing a bottom-up, patient-level quantification of the incremental costs attributable to resistance, this study offers a robust empirical basis for informing public health policies, economic evaluations, and prioritization of interventions aimed at mitigating antimicrobial resistance. Despite some limitations, the analytical framework proposed here can be readily adapted to similar hospital datasets in other countries.